Endoluminal treatment method and associated surgical assembly including tissue occlusion device

ABSTRACT

A surgical instrument includes a hollow member having a sidewall provided with a window and a closure member movably connected to the hollow member for alternately covering and uncovering the window. The hollow member has a first clamping surface along an edge of the window, while the closure member has a second clamping surface opposing the first clamping surface and disposable substantially adjacent thereto in a clamping or closure configuration of the instrument. The instrument additionally comprises a tissue occlusion component mounted to at least one of the hollow member and the closure member for acting on tissues gripped between the first clamping surface and the second clamping surface, to couple the tissues to each other.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.15/361,457, filed Nov. 27, 2016, which is a continuation of U.S.application Ser. No. 14/511,694, filed Oct. 10, 2014, no U.S. Pat. No9,661,984, which is a divisional of U.S. application Ser. No.12/547,296, filed Aug. 25, 2009, now U.S. Pat. No. 9,039,601, which is adivisional of U.S. application Ser. No. 11/197,965, filed on Aug. 5,2005, now U.S. Pat. No. 8,100,822, which is a continuation-in-part ofU.S. application Ser. No. 10/801,283, filed Mar. 16, 2004, now U.S. Pat.No. 7,118,528, the entire disclosures of which applications and patentsare herein incorporated by reference.

FIELD OF THE INVENTION

This invention relates to the surgical treatment of tissue masseslocated inside the human body and particularly along the walls of hollowinternal organs such as the colon. The invention is particularly but notexclusively suitable for use in the treatment of hemorrhoids. Thisinvention also relates, more specifically, to a hemorrhoid treatmentmethod wherein the base of a hemorrhoid is compressed by jaws of aclamping instrument, and then the vascular supply of the hemorrhoid isoccluded by application of an impact or energy. This invention alsorelates to an instrument assembly designed to accomplish this task.

BACKGROUND OF THE INVENTION

There are a variety of abnormal conditions in the human or animal bodywhich are limited to the internal linings of the hollow organs. Colonicpolyps, intestinal arteriovenous malformations, endothelial vascularlesions, abnormal venous valves, and complicated internal hemorrhoidsare just few examples. Other conditions may involve the full thicknessof the wall of the hollow organ as in a colonic perforation, an invadingmalignant tumor, etc. An endoluminal approach to such abnormalconditions may be highly beneficial to the patient since a surgicalaccess trauma is essentially eliminated,

One common condition that is relatively easily treated using anendoluminal approach are complex hemorrhoids. These are traditionallytreated utilizing a variety of interventional and non-interventionalendoluminal methods. An immediate proximity of internal hemorrhoids tothe external orifice allows for a fairly easy access. Severaltechnologies are available on the market and are reviewed below. They,however, carry well-known limitations related to cost, technicalcomplexity and/or poor clinical outcomes.

Hemorrhoidal disease is a very common condition, affecting more thanhalf of people at age 50. Approximately 500,000 patients receive one oranother type of interventional treatment annually in the United Statesfor symptomatic hemorrhoids. Approximately 160,000 patients a year inthe U.S. undergo surgical excision of hemorrhoids.

The term “hemorrhoid” is generally used to refer to the disturbingperianal symptoms related to vascular complexes in the lower rectum andanus. This is usually associated with enlargement of this naturallyoccurring vascular tissue, which is responsible for its subsequentbleeding, prolapsing, thrombosis, itching, burning, etcetera. The word“hemorrhoids” originates from Greek “haimorrhoos” (haimo—hemo+rhein—toflow), which means “flowing with blood.” The word “pile” is a synonymfor hemorrhoid, which originates from Latin “pila”—“ball.”

Repetitive straining due to constipation appears to be a leading factorin forming and progressing of hemorrhoids. The chances of havingsymptomatic hemorrhoids increase with age, pregnancy, obesity,sedimentary life, heavy lifting and genetic predisposition.

The rectum is arbitrarily separated from the anus by the so-calleddentate line. Rectal mucosa is free of pain receptors. The procedureslimited to the rectal mucosa, therefore, generally are not associatedwith pain. In contrast, anal mucosa contains many pain receptors and is,therefore, very sensitive to painful stimuli. Hemorrhoids, located inthe rectum, are called internal. Internal hemorrhoids are located withinthe submucosal layer. External hemorrhoids are located in the anus.Internal and external hemorrhoids have generally different clinicalpresentation and complications. Internal hemorrhoids are prone tobleeding and prolapsing outside of the anal ring. A prolapsed internalhemorrhoid can easily become traumatized and strangulated by a spasticanal sphincter. External hemorrhoids may rupture, causing painfulsubcutaneous lumps in the perianal area, which is frequently referred toas “thrombosed external hemorrhoids”. Thrombosis of external hemorrhoidmay lead to ulceration of the overlying tissues and bleeding. Both typesof hemorrhoids may be responsible for perianal discomfort, itching,irritation, impeding of perianal hygiene, loss of work time andmeasurable decrease of quality of life.

Treatment is tailored to the type and severity of hemorrhoids.Pharmacological treatment, which is aimed at the regulation ofdefecation and symptomatic relief, is notorious for having onlytemporary and frequently incomplete effect. Current interventional,non-excisional, therapies are designed to obliterate blood supply topart of or to the entire hemorrhoid (rubber band ligation, infraredcoagulation, injection sclerotherapy, ultrasound guided hemorrhoidalartery ligation). These have modest, inconsistent clinical success withfrequent recurrences.

Rubber band ligation is the most popular method of treatment ofhemorrhoids in the United States. The technique was described byBlaisdell in 1963. It is quick and not expensive. In this procedure,some hemorrhoidal tissue is pulled into the ligator and a rubber band isplaced around the base of the pulled tissue. This causes essentially astrangulation of the blood supply to a portion of the internalhemorrhoid and its overlying rectal mucosa. An ischemic necrosis andautoamputation of the hemorrhoid follows in a few days, leaving an openrectal wound, which heals over several days. Significant postproceduralpain, affecting daily routine, is rare and is probably related to theplacement of the band too close to the dentate line (pain-sensitivearea). Although rubber band ligation is very effective for immediatebleeding control of small internal hemorrhoids, frequently severaltreatments of a single larger hemorrhoid are required in order toachieve substantial size reduction. Since the significant portion of thehemorrhoid is usually not removed, recurrences are frequent.

In addition, since this treatment leaves the patient with an open woundin the anus for several days or weeks, rubber band ligation might berendered unsuitable for HIV-positive patients and requires demandingpreparation for patients with inherited, acquired and iatrogeniccoagulopathy.

Sclerotherapy is another method to treat first- and second-degreeinternal hemorrhoids. The delivery of a sclerosing agent is accomplishedthrough a single fine needle, attached to the syringe, and is intendedto be within the vascular lumen. Since a hemorrhoid is essentially aball of multiple twisted vascular lumens, it is virtually impossible todeliver sclerosing agent with the desired precision. The rates ofcomplications and recurrence are high.

Ultrasound guided hemorrhoidal artery ligation involves manual suturingof the rectal tissues containing the hemorrhoidal artery. The artery islocated by the ultrasound. A resulting regression of the correspondinginternal hemorrhoid is expected. Since suture-ligation is performedabove the internal hemorrhoid in the pain-insensitive zone, theprocedure should be painless. The technique is demanding and is highlydependent on the operator's experience and dexterity. Inexperience orlack of skill is responsible for both “missing” the hemorrhoidal arteryand inadvertent rectal and vascular injuries. Hemorrhoidal arteryinjuries with resulting severe bleeding, rectal wall injury, etc. havebeen reported. Recurrences are frequent.

Infrared coagulation of a hemorrhoidal artery involves delivery of theinfrared coagulation energy to the hemorrhoidal artery and causessubsequent regression of the corresponding internal hemorrhoid. Sincethe exact location of the artery is not known and is only presumed to bejust proximal to the internal hemorrhoid, several blind infrared firingsare required to improve the chance of reaching the hidden target.Several sessions of treatments in a time span of several weeks isrecommended. The proper application of the infrared probe is moredifficult with larger hemorrhoids due to obscurity of the interfacebetween the probe and mucosa. Recurrences are frequent.

None of the above described techniques adequately addresses tissueredundancy and tissue prolapse, which frequently accompany more advancedstages (late 2^(nd), 3^(rd) and 4^(th)) of hemorrhoidal disease and,therefore, can be considered only for the treatment of 1^(st) and early2^(nd) stages of internal hemorrhoids. Even then, the rate of recurrenceis substantial, reflecting the deficiencies of the existing methods.

The only approach which has been found to be consistently effective inthe long-lasting control of the hemorrhoidal symptoms is the surgicalexcision of the hemorrhoids. There are two main methods of surgicalexcision of internal hemorrhoids: traditional surgical excisionlongitudinal hemorrhoidectomy) and the so-called Procedure for Prolapseand Hemorrhoids or PPH (transverse hemorrhoidectomy with circularstapler).

Traditional surgical excision of hemorrhoids is a very effective butdebilitating form of treatment. The hemorrhoidal tissue essentially isremoved in longitudinal fashion down to the underlying internalsphincter. Traditional surgical excision almost invariably extends theanal trauma to and beyond the dentate line, thus causing severepostoperative pain. The technique is highly dependent on the technicalskill of the operator. Surgical excision of hemorrhoids requiresanesthesia and causes severe perianal pain for several weeks andsignificant loss of work time.

The so-called Procedure for Prolapse and Hemorrhoids (PPH) involvescircumferential excision of the rectal mucosa and submucosal layer witha circular stapler, proximal to the internal hemorrhoids. The procedureis essentially directed towards a radical devascularization of thehemorrhoids while the hemorrhoidal tissue itself is left to ischemicallyregress. Since excision is done in the pain insensitive area (above thedentate line), a decreased postoperative pain and faster recovery whencompared to traditional hemorrhoidectomy are observed. The internalhemorrhoids purportedly shrink within four to six weeks after theprocedure. Advocates of PPH claim less pain and faster recovery, but thetechnique requires anesthesia and a demanding technical and instrumentalset-up. In addition, this technique creates substantial circumferentialrectal trauma, which is clearly excessive in the majority of cases whenonly 1 or hemorrhoids are enlarged. Serious complications have beenreported. A substantial circumferential injury of the anal canal andsubsequent scarring may cause rectal stricture (narrowing), which isdebilitating and difficult to treat. The technique requires massive analdilation in order to accommodate a large head assembly of the circularstapler, which by itself presents an additional source of postoperativeanal discomfort and potential anal trauma (anal fissures, bleeding,etc.). The main achievement of PPH technique over traditionalhemorrhoidectomy is the placement of the surgical injury line intransverse fashion above the dentate line.

In summary, although many minimally invasive techniques have beenintroduced to treat symptomatic internal hemorrhoids, these entail ahigh rate of recurrence and a need for repetitive procedures.Approximately 15-20% of patients undergoing an intervention fortreatment of their internal hemorrhoids require surgical excision ofhemorrhoids, mainly because the current non-excisional techniques do notaddress or address inadequately (rubber band ligation) the accompanyinganal mucosa} prolapse and tissue redundancy. Some groups of patients,such as HIV-positive patients, and patients with spinal cord injuries,coagulopathy, etc., have absolute or relative contraindications to theexisting techniques. The Procedure for Prolapse and Hemorrhoidsaddresses many of the deficiencies of the existing techniques, butinvolves a demanding technical and instrumental set-up, requires generalor regional anesthesia, and is designed to perform frequentlyunnecessary circumferential rectal injury.

There is a need, therefore, for a device which allows fast and effectivetreatment of hemorrhoids in minimally invasive (innocent tissues arespared) and painless fashion (excisional line is placed above thedentate line).

OBJECTS OF THE INVENTION

It is an object of the present invention to provide an improved methodfor the surgical treatment of internal tissues located along the wallsof internal body organs or lumens such as the colon.

It is a more specific object of the present invention to provide such amethod that is useful in the treatment of hemorrhoidal tissues.

It is another specific object of the present invention to provide asurgical method that is less traumatic than prior art methods for thesurgical treatment of hemorrhoids.

A further relatively specific object of the present invention is toprovide a surgical method for the treatment of hemorrhoids, that mayappropriately be carried out in an office, rather than requiring anoperating room.

It is a related object of the present invention to provide an anoscopethat may be used in carrying out the method of the invention.

Another related object of the present invention is to provide aninstrument assembly including a tissue occlusion device that may be usedin carrying out the method of the invention.

A further object of the present invention is to provide a surgicalinstrument assembly for treating one or more hemorrhoids with anyseverity of enlargement and prolapse.

Yet another object of the present invention is to provide a methodand/or an associated instrument assembly that may be used with anendoscope to access surgical sites in natural body lumens where thesurgical sites are far removed from natural body openings.

These and other objects of the present invention will be apparent fromthe drawings and descriptions herein. Although every object of theinvention is believed to be attained in at least one embodiment of theinvention, there is not necessarily any single embodiment that attainsall of the objects of the invention.

SUMMARY OF THE INVENTION

The present invention is directed in part to providing a device and anassociate method for the treatment of hemorrhoids. The device can alsobe utilized for the treatment of other pathologies in locations remotethat are from natural body openings. Accordingly, the invention isdirected in part to an endoluminal intervention assembly that includesan accessory system for the delivery and support (optically andmechanically) of instrumentation to surgical sites remote from thenatural openings.

A surgical instrument comprises, in accordance with the presentinvention, a hollow member having a sidewall provided with a window, anda closure member movably connected to the hollow member for alternatelycovering and uncovering the window. The hollow member has a firstclamping surface along an edge of the window, while the closure memberhas a second clamping surface opposing the first clamping surface anddisposable substantially adjacent thereto in a clamping or closureconfiguration of the instrument. The instrument additionally comprises atissue occlusion component mounted to at least one of the hollow memberand the closure member for acting on tissues gripped between the firstclamping surface and the second clamping surface, to couple the tissuesto each other.

In an endoscopic embodiment of the invention, the hollow member has achannel for receiving an insertion member of an endoscope, and thehollow member includes a chamber located laterally relative to thechannel, the window communicating with the chamber. The closure membermay be slidably inserted in another channel in the hollow member. Thehollow member may be provided with a plurality of light access openingsfor permitting visual inspection of the chamber from outside the hollowmember. The hollow member or the endoscope is in this case provided withlight guide components such as optical fiber bundles for conveyingillumination to the chamber and for transmitting images from the chamberto a viewer such as a video monitor or eyepiece. The hollow member ofthe endoscope may be further provided with one or more working channelsthat communicate at the distal ends with the chamber for enabling theinsertion of endoscopic instrument tips into the chamber.

In accordance with another feature of the present invention, thesidewall of the hollow member is curved and at least one of the firstclamping surface and the second clamping surface has a curved form,e.g., a C shape or U shape.

Where the closure member is slidably connected to the hollow member, thefirst clamping surface and the second clamping surface may staysubstantially parallel to one another during opening and closing strokesof the closure member. Also, where the hollow member has a longitudinalaxis, the first clamping surface and the second clamping surface mayextend in planes oriented substantially perpendicularly to the axis,while the closure member is movable parallel to the axis.

In an alternate embodiment of the present invention, the hollow memberis provided with a channel, the closure member is disposed in part inthe channel, and the window communicates with the channel.

Pursuant to one embodiment of the present invention, the hollow memberis closed at one end, and is provided with a handle at an opposite end.The closure member may also be provided, at an end opposite the secondclamping surface, with a handgrip extending parallel to the handle.

The tissue occlusion component may be a stapling mechanism an injectionmechanism connectable to a reservoir of a sclerosing composition, oroptical fibers connectable to a source of laser radiation. Other kindsof tissue occlusion device will be apparent to those skilled in the art.

A surgical instrument comprises, in accordance with the presentinvention, a hollow body defining a longitudinal channel, the hollowbody being at least partially open at a proximal end, the hollow bodyhaving a sidewall provided with a window spaced from the proximal end.The surgical instrument further comprises a shutter or closure membermovably mounted to the hollow body to cover the window during apositioning of the hollow body in a body lumen, the shutter or closuremember being removable from the window to permit organic tissues toprotrude through the window.

The window may be located in a bulging portion of a sidewall of thehollow body of the instrument.

In an embodiment of the invention particularly suitable for use with anendoscope, (a) the hollow body has a chamber disposed in the bulgingportion, (b) the window communicates with the chamber, (c) the hollowmember is fanned with a partition separating the channel from thechamber, and (d) the channel is dimensioned for receiving an insertionmember of an endoscope. Thus, in this embodiment of the invention, theinstrument is designed for coupling to an endoscope for insertion into apatient together with a distal end portion of the endoscope. The shutteror closure member may be slidably disposed in the hollow body.

A surgical method in accordance with the present invention utilizes aninstrument assembly including a hollow body member having a sidewallformed with a window and further including a tissue occlusion component,the occlusion component defining a pair of jaws, at least one of thejaws including an arcuate clamping surface. The method comprises (i)inserting the hollow body member into a body lumen of a patient, (ii)manipulating the hollow body member so that organic tissues protrudethrough the window into the hollow body member, (iii) after theprotruding of the tissues through the window, manipulating the occlusioncomponent so that the jaws are located on opposite sides of theprotruding tissues, (iv) thereafter closing the jaws to clamp theprotruding tissues, and (v) subsequently operating the occlusioncomponent to permanently constrict a portion of the protruding tissues.

Where the instrument assembly includes a shutter or closure member forcovering the window, the inserting of the hollow body member into thebody lumen typically includes inserting the hollow body member with theshutter or closure member covering the window, while the method furthercomprises moving the shutter or closure member to uncover the window topermit the organic tissues to protrude through the window.

The moving of the shutter or closure member may include sliding theshutter or closure member relative to the hollow body member.

The method may additionally comprise attaching the hollow body member toan insertion member of an endoscope, so that the inserting of the hollowbody member into the body lumen includes inserting the endoscope withthe hollow body member attached thereto into the body lumen.

Where the hollow body member has a channel and a chamber, the windowcommunicating with the chamber, the attaching of the hollow body memberto the insertion member includes inserting the endoscope insertionmember into the channel of the hollow boy member, and the method furthercomprises visualizing the protruding tissues in the chamber via anoptical system having access to the chamber.

The present invention offers to provide minimally invasive treatment ofone or more hemorrhoids through an anal cannula having a normal size orany degree of enlargement and protrusion. The approach of the presentinvention recommends the application of a staple line in a transversedirection (in relation to the anal axis) above the so-called dentateline (the dentate line is an anatomical line in the anal canal, abovewhich the mucosa is pain-insensitive). Since the C-curve of thetissue-occluding jaws in a closure device of the present invention isessentially a circular section, all the advantages of circular staplingcan be attained in the present methodology without the disadvantages. Asmaller stapling cartridge or jaws with a different C-curve (more orless curved) can be used for smaller hemorrhoids or different rectums asneeded without the potential of rectal narrowing or substantialcollateral ano-rectal trauma, which accompany the method of U.S. Pat.No. 6,142,933. The particular anal port or anoscope design of thepresent invention, together with the C-curved stapler clamp, allowstreatment of the chosen number of hemorrhoids without incurringunnecessary surgical trauma and expense. The anoscope andtissue-occluding device of the present invention can be used in theoffice without the need for trained medical assistance. Less surgicaltrauma, particularly in the treatment of hemorrhoids, translates into areduced loss of work and interruption of normal life.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view, partially broken away, of ananoscope in accordance with the present invention, for use in a methodin accordance with the present invention, showing a pair of jaws.

FIG. 2 is a schematic perspective view, partially broken away, of atissue occlusion device in accordance with the present invention, foruse in a method in accordance with the present invention.

FIG. 3 is a schematic perspective view of a proximal one of the jawsdepicted in FIG. 1, showing details of a tissue occlusion mechanism.

FIG. 4 is a schematic perspective view of the proximal jaw of FIG. 1,showing details of another tissue occlusion mechanism.

FIG. 5 is a schematic perspective view of the proximal jaw of FIG. 1,showing details of a further tissue occlusion mechanism.

FIG. 6 is a schematic perspective view of the proximal jaw of FIG. 1,showing details of yet another tissue occlusion mechanism.

FIGS. 7A-7F are schematic cross-sectional views of the anoscope of FIG.1 inserted into an anal canal, showing successive steps of a method inaccordance with the present invention.

FIG. 8 is a schematic transverse cross-sectional view taken along lineIX-IX in FIG.

7D.

FIG. 9 is a schematic transverse cross-sectional view taken along lineVIII-VIII in FIG. 7C.

FIG. 10 is a diagrammatic transverse cross-section of the anoscope ofFIGS. 1 and 7A-7F.

FIG. 11 is a diagrammatic transverse cross-section similar to FIG. 10,showing an alternative design of the anoscope of FIGS. 1 and 7A-7F.

FIG. 12 is a diagrammatic transverse cross-section similar to FIG. 10,showing another alternative design of the anoscope of FIGS. 1 and 7A-7F.

FIG. 13 is a side elevational view of an anoscope with an includedtissue occlusion component, in accordance with the present invention.

FIG. 14 is a bottom, front and left side perspective view of the tissueoccluding anoscope of FIG. 13.

FIG. 15 is a top, rear, and left side perspective view of the tissueoccluding anoscope of FIGS. 13 and 14.

FIG. 16 is a top, rear, and left side perspective view of the tissueoccluding anoscope of FIGS. 13-15, in longitudinal or axial section.

FIG. 17 is a longitudinal cross-sectional view of the tissue occludinganoscope of FIGS. 13-16, showing a shutter or closure member in an openor tissue receiving position.

FIG. 18 is a view similar to FIG. 17, showing the shutter or closuremember in a closed or unclamping position.

FIG. 19 is a schematic top plan view of an embodiment of an endoscopictissue occlusion assembly in accordance with the present invention.

FIG. 20 is a schematic bottom view of the endoscopic tissue occlusionassembly of FIG. 19.

FIG. 21 is a schematic longitudinal cross-sectional view of the tissueocclusion assembly of FIGS. 19 and 20, taken along line XXI-XXI in FIG.19.

FIG. 22 is a schematic cross-sectional view of the tissue occlusionassembly of FIGS. 19-21, taken along line XXII-XXII in FIG. 20.

FIG. 23 is a schematic bottom view of another embodiment of anendoscopic tissue occlusion assembly in accordance with the presentinvention.

FIG. 24 is a schematic longitudinal cross-sectional view of the tissueocclusion assembly of FIG. 23, taken along line XXIV-XXIV in FIG. 23.

FIG. 25 is a schematic longitudinal cross-sectional view similar to FIG.24 prior to formation of the expanded chamber.

DETAILED DESCRIPTION

As illustrated in FIG. 1, an anoscope 20 for hemorrhoidal surgerycomprises a hollow body 22 and a shutter member 24. Hollow body 22defines a longitudinal channel or lumen 26 that is closed at a distalend 28 and formed with an opening 30 at a proximal end 32. Opening 30enables visual inspection of a surgical site and the insertion ofinstrumentation. Hollow body 22 has a sidewall 34 provided with arectangular window 36 spaced from distal end 28 and preferably also fromproximal end 28 of hollow body 22.

Shutter member 24 is movably mounted to hollow body 22 to cover window36 during a positioning of anoscope 20 in an anal canal. Shutter member24 is removable from window 36 to permit hemorrhoidal tissues toprotrude through window 36 into anoscope channel 26. More specifically,shutter member 24 is slidably mounted to hollow body 22, is disposed inhollow body 22, and has a shape conforming to sidewall 34 in a regionthereof about window 36.

Shutter member 24 is located in a track 37 in the hollow body. Track 37takes the form of a shallow depression or recess with longitudinal edgesor shoulders 39 serving as guides for the sliding shutter member 24. Atransverse edge or shoulder 41 serves as an abutment to continued distalmotion of shutter member 24 during an insertion stroke thereof. Shuttermember 24 may be locked into track 37, for example, by grooves (notillustrated) in longitudinal edges or shoulders 39.

Hollow body 22 generally has a longitudinal axis 38, and sidewall 34 isformed with a bulging portion or protrusion 40 located on one side ofthe axis and extending from proximal end 32 of the hollow anoscope bodypartially along a length of sidewall 34 towards distal end 28. Window 36is located in bulging portion 40, and shutter member 24 is slidablealong and in engagement with bulging portion 40. As shown in FIGS. 8,and 9, shutter member 24 and bulging portion 40 may be cooperativelyformed so that the bulging portion serves as a track that slidablyretains the shutter member. Window 36 may generally take any shapesuitable for the admission of protruding hemorrhoidal tissues HT (FIGS.7B-7F, 8, and 9). Rectangular and circular are possible shapes.

Hollow body 22 of anoscope 20 has a rim 42 surrounding opening 30 atproximal end 32. Hollow body 22 is preferably provided along rim 42 witha flange 44 serving as a stop for preventing anoscope 20 from slippingentirely into the anal canal. Hollow body 22 is further provided alongrim 42 with a cutout 46 disposed on a side of axis 38 opposite bulgingportion 40.

Cutout 46 facilitates manipulation of any instrument that is insertedinto anoscope 20 for operating on hemorrhoidal tissues. In addition,cutout 46 facilitates observation of window 36 and of hemorrhoidaltissues HT protruding into longitudinal channel 26 through window 36.

In some applications, window 36 may extend in a proximal direction allthe way to flange 44. In any case, window 36 is large enough for theadmission of hemorrhoids into channel or lumen 26 of anoscope 20. Theplacement of window 36 in bulging portion or protrusion 40 is conduciveto providing window 36 with properly large dimensions.

Anoscope 20 may be provided as part of a surgical instrument assemblythan also includes a hemorrhoid treatment device 48 depicted in FIG. 2.Device 48 comprises an instrument shaft 50, a handle or actuator 52connected to the shaft at a proximal end thereof, and a pair of jaws 54and 56 (proximal and distal) mounted to the shaft at a distal endthereof. Handle 52 is operatively connected to jaws 54 and 56 foralternatively opening and closing the jaws. Jaws 54 and 56 each takesthe form of a C- or U-shaped clamping member movable alternately awayfrom and towards the other jaw.

Jaws 54 and 56 define respective gaps 55 and 57. A distal end portion ofinstrument shaft SO is U- or C-shaped in cross-section and defines arecess 59 aligned and communicating with gap 55. This asymmetrical shapeof the distal end of instrument shaft 50 facilitates a visualization ofa surgical site while a distal end portion of hemorrhoid treatmentdevice 48 is inserted into anoscope 20.

A hemorrhoid occlusion component is mounted to jaws 54 and 56 for actingon tissues gripped between the jaws, to couple the tissues to eachother. The hemorrhoid occlusion component may take any form capable ofbonding organic tissues, particularly hemorrhoidal tissues, to oneanother. As depicted in FIG. 3, the hemorrhoid occlusion component maytake the form of a stapling mechanism 58 including a plurality ofstaples 60 disposed in an arcuate configuration inside proximal jaw 54.Staples 60 are longitudinally aligned on a distal side with respectiveejection apertures 62 in jaw 54 and on a proximal side with respectivepusher elements 64. Pusher elements 64 may be disposed on a proximalside in contact with a pressure application ring (not shown) or otherforce-transmission structure operatively connected at a proximal endwith handle 52. Distal jaw 56 is provided with a series of anvilelements or areas (not shown) that are aligned with respective slots orejection apertures 62, for causing staple closure upon firing.

Staples 60 may be housed in a disposable cartridge element that may be aportion or the entirely of proximal jaw 54. This variation permits asurgeon, proctologist or other medical practitioner to clamp pluralhemorrhoids in the course of a single procedure. After the stapling ofone hemorrhoid, as discussed below with reference to FIGS. 7A-7E, theempty cartridge (e.g., jaw 54) is removed and replaced with a similarloaded staple cartridge.

As illustrated in FIG. 4, an alternative hemorrhoid occlusion componenttakes the form of an injection mechanism 66 including a plurality ofhollow needles 68 fixed to proximal jaw 54. Needles 68 arelongitudinally oriented and circumferentially spaced about jaw 54.Needles 68 are connectable via a distribution manifold 70 to a reservoir72 of a sclerosing composition such as a concentrated sugar solution ora biocompatible adhesive.

FIG. 5 shows another alternative occlusion component in the form of aradiant-energy applicator 74, for instance, in the infrared or opticalportions of the electromagnetic spectrum. More specifically,radiant-energy applicator 74 includes optical fibers 76 connectable viaa distribution manifold 78 to a source 80 of laser radiation.

FIG. 6 depicts yet another alternative occlusion component in the formof an electrode 82 mounted to proximal jaw 54 and facing in the distaldirection towards distal jaw 56. Distal jaw 56 may also be provided withan electrode (not shown), in the case of a bipolar delivery ofelectrical energy. Electrode 82 is connectable to a source 84 ofradio-frequency current for delivering RF cauterizing current tohemorrhoidal tissues.

Jaws 54 and 56, together with rods 86 and 88, may form a disposableocclusion cartridge that is removable from shaft 50. Upon completion ofa hemorrhoid treatment procedure on one patient, the cartridge isremoved and replaced with a new cartridge for use on another patient.

In the case of injection mechanism 66, radiant-energy applicator 74, orelectrode 82, handle 52 may be provided with a port or connector 85 forenabling the coupling of the hand- held hemorrhoid treatment device 48to reservoir 72, laser source 80, or RF electric source 84,respectively.

As further illustrated in FIG. 2, jaws 54 and 56 are mounted to a pairof parallel rods 86 and 88 each connected at a proximal end toinstrument shaft 50. Jaws 54 and 56 are connected to one another and toshaft 50 via rods 86 and 88 so that the jaws remain parallel to oneanother and perpendicular to rods 86 and 88 during opening and closingstrokes of the jaws. Any reciprocatable drive mechanism known in the artor hereafter developed may be operatively coupled to jaws 54 and 56 andhandle 52 for enabling opening and closing of jaws 54 and 56 bymanipulation of handle 52.

In the embodiment of the hemorrhoid treatment device 48 shown in FIG. 2,distal jaw 56 is slidably coupled to rods 86 and 88, proximal jaw 54 isfixed with respect to the rods, and the rods are coupled to distal jaw56 on opposite sides thereof. Jaws 54 and 56 and rods 86 and 88 may bemanufactured as a disposable cartridge assembly detachable frominstrument shaft 50. Alternatively, the operative components, such asstaples 60 and apertures 62, may be formed as parts of a disposablecartridge separate from the jaws 54 and 56.

FIGS. 7A-7F illustrate steps in a method for the treatment ofhemorrhoids utilizing anoscope 20 and hemorrhoid treatment device 48. Asshown in FIG. 7A, anoscope 20 with shutter member 24 closing window 36is inserted through a transparent anal port member 89 into an anal canalAC and is manipulated so that hemorrhoidal tissues HT are disposedadjacent to window 36. This procedure may involve longitudinallyshifting and/or rotating the anoscope 20 inside the anal canal AC untilthe anoscope is in the desired position relative to the hemorrhoidaltissues HT. To that end, shutter member 24 and optionally sidewall 34 ofhollow body 22 are made of a transparent polymeric material. Thus, analtissues can be visualized through sidewall 34 and shutter member 24during the manipulation of anoscope.

Upon an appropriate positioning of anoscope 20, shutter member 24 isgrasped at an external flange or finger grip 90 and pulled in a proximaldirection as indicated by an arrow 92 in FIG. 7B. This action uncoverswindow 36 and enables hemorrhoidal tissues HT to protrude through thewindow into channel 26 of anoscope 20. Subsequently, a distal endportion of hemorrhoid treatment device 48 particularly including jaws 54and 56 is inserted into anoscope 20. As depicted in FIG. 7C, thisinsertion may be performed with jaw 54 and 56 located in channel 26 on aside of longitudinal axis 38 opposite bulging sidewall portion 40 (seeFIGS. 7C and 8), whereby the protruding hemorrhoidal tissues HT passthrough a slot or gap 94 defined by jaw 56. In that case, after theplacement of hemorrhoid treatment device 48, the device is rotated abouta longitudinal axis and possibly translated orthogonally to that axis toalign jaws 54 and 56 with a neck or base region 96 of the protrudinghemorrhoidal tissues HT as shown in FIGS. 7D and 9.

In an alternative deployment procedure, the distal end portion ofhemorrhoid treatment device 48 is inserted into anoscope 20 in such amanner that jaws 54 and 56 are located in channel 26 on the same side oflongitudinal axis 38 as bulging sidewall portion 40 (see FIGS. 7C and8). Because the protruding hemorrhoidal tissues HT are malleable, distaljaw 56 of hemorrhoid treatment device 48 may be slipped past theprotruding tissues. It may be necessary or expedient to wigglehemorrhoid treatment device 48 during the insertion (and removal) phaseof a deployment operation, depending on the relative sizes of anoscope20, hemorrhoid treatment device 48, and the protruding hemorrhoidaltissues HT. In this alterative deployment procedure, there is no need torotate device 48 about a longitudinal axis to align jaws 54 and 56 witha neck or base region 96 of the protruding hemorrhoidal tissues HT asshown in FIGS. 7D and 9.

With jaws 54 and 56 located on opposite sides of hemorrhoidal tissuesHT, they are approximated, as depicted in FIG. 7E, to clamp thehemorrhoidal tissues HT. Preferably, jaws 54 and 56 are maintained inparallel to one another during their closing and opening strokes.

While jaws 54 and 56 are clamped about neck region 96 of tissues HT asshown in FIG. 7E, the tissue occlusion component (FIGS. 3-6) of thehemorrhoid treatment device 48 is operated to permanently constricthemorrhoidal tissues HT in or about neck region 96. In the case ofstapling mechanism 58 (FIG. 3), staples 60 are fired through ejectionapertures 62 in jaw 54 by a distal motion of pusher elements 64, thestaples being closed upon meeting respective anvil elements (notillustrated) in distal jaw 56. In the case of injection mechanism 66(FIG. 4), hollow needles 68 fixed to proximal jaw 54 are naturally orautomatically inserted into hemorrhoidal tissues during theapproximation of jaws 54 and 56. Sclerosing composition is then guidedfrom reservoir 72 into the hemorrhoidal tissues HT. In the case ofradiant-energy applicator 74 (FIG. 5), the applicator is operated togenerate electromagnetic radiation of a predetermined spectral range,which is then directed into hemorrhoidal tissues HT via optical fibers76. In the case of the RF-cautery componentry of FIG. 6, radio-frequencycurrent is conducted from source 84 through electrode 82 intohemorrhoidal tissues HT. Where distal electrode 56 is also provided withan electrode, the current passes from electrode 82 through neck or baseregion 96 to jaw 56.

In the case of a monopolar cauterization current, the current spread outfrom tissues HT into the patient's body.

After the occlusion operation has been performed, handle 52 is operatedto separate jaws 54 and 56 from one another and the treatment device 48is manipulated to separate the jaws from the treated hemorrhoidaltissues HT (FIG. 7F). Treatment device 48 is then further manipulated towithdraw it from anoscope 20. Again, because of the deformability of theclamped hemorrhoidal tissues HT, in many cases it will be possible tosimply withdraw the hemorrhoid treatment device 48 without rotation, butperhaps with some wiggling.

The hemorrhoidal tissues HT distal to the occluded neck region 96 may betransected with a scalpel or allowed to ischemically regress orself-amputate. Self-amputation occurs within a few days of the occlusionprocedure. Ischemic regression takes place within several weeks.Ischemic regression and self-amputation are the result of occlusion ofbloods vessels in neck or base region 96.

Bulging portion or protrusion 40 of anoscope 20 serves as a retractor ofcollateral anal or rectal tissues. In addition, bulging portion orprotrusion 40 creates more work space in the area of hemorrhoidaltissues HT. This design allows for better access to the neck or base 96of tissues HT, which is located in the submucosal layer close to therectal muscle.

FIGS. 8-10 show one configuration of bulging portion or protrusion 40,where the protrusion has a radius of curvature that is greater than aradius of curvature of the remaining part of hollow body 22. Otherconfigurations are possible. FIG. 11 depicts a configuration where abulging portion or protrusion 98 has a radius of curvature that issmaller than the radius of curvature of the main part of hollow bodymember 22. FIG. 12 illustrates a configuration where a bulging portionor protrusion 100 has a radius of curvature that is essentially equal tothe radius of curvature of the main part of hollow body member 22. Thedashed lines 102, 104, 106 represent the respective occluding jaws ofhemorrhoid treatment device 48.

Generally, the manipulating of anoscope 20 to align window 36 withhemorrhoidal tissues is performed after the inserting of anoscope 20into the anal canal. Anoscope 20 and port member 89 are preferably madeof a transparent polymeric material that facilitates visual inspectionand locating of the hemorrhoids. Jaws 54 and 56 of the occlusion deviceare inserted into anoscope 20 after the inserting of anoscope 20 intothe anal canal AC, after the manipulating of anoscope 20 to align window36 with hemorrhoidal tissues HT, and after the protruding of thehemorrhoidal tissues HT through window 36.

A hemorrhoid treatment instrument or device as disclosed hereinabove maybe partially or completely disposable. Where both jaws 54 and 56 areparts of a disposable cartridge removably attached to shaft 50, theproximal portion of the instrument may be utilizable in treatingdifferent patients at different times. Alternatively or additionally,where proximal jaw 54 contains a staple magazine, jaw 54 may bereplaceable to permit multiple hemorrhoid occlusion procedures on thesame patient. FIGS. 13-18 depict a surgical instrument assembly and moreparticularly a tissue-occluding anoscope assembly 120 for the treatmentof hemorrhoids. The instrument assembly 120 comprises a hollow member122 having a sidewall 124 provided with a window 126 and furthercomprises a closure member 128 slidably connected to the hollow memberfor alternately covering and uncovering the window. Hollow member 122has a first clamping surface 130 along an edge of window 126. Closuremember 128 has a second clamping surface 132 opposing clamping surface130 and disposable substantially adjacent thereto in a clamping orclosure configuration of the instrument shown in FIGS. 13-15 and 18.Closure member 128 is slidable in a proximal direction, away fromclamping surface 130 to open window 126, as shown in FIGS. 16 and 17.

Tissue occluding instrument assembly 120 additionally comprises a tissueocclusion component 134 mounted to at least one of the hollow member 122and the closure member 128 for acting on organic tissues gripped betweenclamping surfaces 130 and 132, to couple the tissues to each other.Tissue occlusion component 134 may be a stapling mechanism, an injectionmechanism connectable to a reservoir of a sclerosing composition, oroptical fibers connectable to a source of laser radiation.

Sidewall 124 of hollow member 122 is generally conically curved, so thatclamping surfaces 130 and 132 have a curved form, e.g., a C shape or Ushape. Clamping surfaces 130 and 132 lie in parallel planes that extendperpendicularly to a longitudinal axis 136 of instrument 120 and remainparallel to one another during opening and closing strokes of closuremember 128. Closure member 128 moves parallel to axis 136.

Hollow member 122 is closed at a distal end 138 and defines alongitudinal channel 140 in which closure member 128 is disposed inpart. Window 126 communicates with channel 140. At a proximal end,opposite closed end 138, hollow body 122 is provided with a handle 142including a extending longitudinally stem 144 (that is oriented at asmall angle relative to axis 136) and a substantially transverselyextending handgrip 146. Closure member 128 includes a main part 148formed as a channel member and, at an end of main part 148 oppositeclamping surface 132, a handgrip 150 extending parallel to handgrip 146of handle 142. Stem portion 144 of handle 142 is formed as a channelmember that slidingly receiving main part 148 of closure or shuttermember 128.

FIGS. 19-22 depict an endoscopic version of a tissue occludinginstrument assembly 152 including a hollow body member 154 that has achannel 156 for receiving an insertion member 158 of an endoscope.Hollow member 154 incorporates a chamber 160 that is located laterallyrelative to channel 156. Chamber 160 is optionally separated fromchannel 156 by a partition or wall 162. Endoscope insertion member 158extends in an arc about chamber 160, which is accordingly located in abulging portion 164 of hollow body member 154.

Hollow body member 154 and particularly bulging wall 164 thereof isprovided with a window or aperture 166 through which organic tissuessuch as a polyp 168 may protrude during an endoscopic tissue occludingprocedure. During such a procedure, endoscope insertion member 158, withhollow body member 154 attached thereto as illustrated, is insertedthrough a natural body opening such as the anal orifice into an internallumen such as the colon. Optical components (not illustrated) in thedistal end face 170 of endoscope insertion member 158 are used tovisually inspect the walls of the body lumen and to detect a surgicalsite containing polyp 168 or other undesirable tissue mass.

Tissue occluding instrument assembly 152 further includes a closure orshutter member 172 that includes a tissue clamping surface 174 at adistal end. Surface 174 generally has an arcuate shape and lies in aplane transverse to a longitudinal axis 176 of the instrument assembly.Surface 174 is opposable to another arcuate tissue clamping surface 178that is attached to hollow body member 154 along a distal edge (notseparately labeled) of window 166. Surface 178 also lies in a planetransverse to a longitudinal axis 176 and is accordingly parallel tosurface 174.

Closure or shutter member 172 is attached to a distal end of a rod 180that is slidably disposed in a channel 182 of hollow body member 154that extends parallel to axis 176. During an initial phase of adeployment operation, rod 180 is pushed in a distal direction so thatclosure or shutter member 172 covers or closes opening 166. Upon thereaching of a contemplated surgical site, rod 180 is pulled in aproximal direction to remove closure or shutter member 172 from window166 and allow polyp 168 to protrude through window 166 into chamber 160.

Body member 154 is provided in chamber 160 with an opening 184 via whicha visual inspection of chamber 160 may be undertaken. Opening 184 mayprovide visual access to chamber 160 via optical components of endoscopeinsertion member 158 (exemplarily including anillumination source, alens, and an optical fiber bundle—none illustrated). Alternatively, asdiscussed hereinafter with reference to FIGS. 23 and 24, hollow bodymember 154 may be provided with its own dedicated optical components forestablishing visual access to chamber 160.

Hollow body member 154 may additionally be provided along chamber 160with openings 186 for enabling access to chamber 160 by the working tipsof endoscopic instruments such as a suction device 188. Suction device188 includes a conical head 190 that engages polyp 168. Upon anapplication of suction, device 188 is pulled in proximal directionthrough a working channel 192 of endoscope insertion member or hollowbody member 154. Thus, polyp 168 is stretched out to facilitate anocclusion operation in which closure or shutter member 172 is moved inthe distal direction so that pedicle or neck tissues 194 of polyp 168are sandwiched between clamping surfaces 174 and 178. Occlusioncomponentry 196 then operates through clamping surface 178 and/orsurface 176 to effectuate an occlusion of the pedicle or neck tissues194. Occlusion componentry 196 exemplarily takes the form of a staplingmechanism, an injection mechanism connectable to a reservoir of asclerosing composition, or optical fibers connectable to a source oflaser radiation. In any of the embodiments of a tissue occludinginstrument assembly disclosed herein, the tissue occluding componentrymay effectuate a heating of the tissues via resistive heat producingelements or electrical current transmission components.

At the termination of the procedure discussed above with reference toFIGS. 19-22 as in other procedures contemplated herein, closure orshutter member 172 is opened after the application of the occlusionenergy. The occluded tissue mass, e.g., polyp 168, is then allowed toslip out of chamber 160 back into the natural body lumen.

FIGS. 23 and 24 depict a tissue occluding instrument assembly 202similar to instrument assembly 152 of FIGS. 19-22. In assembly 202, ahollow body member 204 having a channel 206 receiving an endoscopeinsertion member 208 incorporates a fiber- optic illumination guide 210,a fiber-optic image guide 214, at least one working channel 216 for thedeployment of endoscopic instrument, cables 218 and 220 for assisting incurving endoscope insertion member 208 to form a chamber 222 adjacent206 as can be appreciated by comparing FIGS. 24 and 25. A stiffening rod224 may be insertable through a channel 226 of hollow body member 205also for purposes of assisting the formation of chamber 222.

Thus, hollow body member 204 may take the form of an endoscope sheaththat is deformable at a distal end to expand chamber 222 from acollapsed insertion configuration to an expanded use configuration asshown particularly in FIG. 24. Illumination guide 210 and image guide214 terminate distally at light access openings 212 and 228 along thewall of chamber 222.

A first arcuate clamping surface 230 is located on hollow body member204, along a distal edge of a window 232 that communicates with chamber222. A second arcuate clamping surface 234 is attached to the distal endof a closure or shutter member 236. Closure or shutter member 236 isconnected to a rod 238 that moves the closure member alternately in adistal and proximal direction for effectuating a closure of window 232during an insertion operation, an opening of window 232 to enable aprotruding of a tissue mass into chamber 222, and a clamping of theprotruding tissues during an application of energy to the tissues toeffectuate an occlusion thereof. Tissue occluding componentry 240provided on closure member 236 at surface 234 may take the form of anyof the instrumentalities discussed above.

A suction head 242 of a suction device 244 inserted through workingchannel 216 may be used to draw a polyp 246 away from a wall 248 of abody lumen to facilitate a tissue occluding operation.

Tissue occluding instrument assemblies 152 and 202 may be used to treata variety of pathologies (polyp, wall perforation, bleeding point at apreviously placed staple line, etc.) but are generally not useful fortreating hemorrhoids. Endoluminal tissue occluding instrument assemblies152 and 202 may be used for treatment of lesions in natural andartificial lumens other than the colon, including the trachea, thebronchi, blood vessels (arteries and veins), etc.

Other known types of surgical maneuvers/operations can be performedusing tissue occluding instrument assemblies 152 and 202, such asoperating on an intimal/endothelial lesion in a vessel (arterial plaque,etc.) or operating on diseased venous or arterial valves. To carry outsuch additional procedures, a wide range of endoscopic surgicalinstruments (scissors, grasper, dissector, clip applier, etc.) can beintroduced via endoscopic sheath channels 192, 216 to the targetedtissues.

Where organic tissues are to be severed and then extracted from thepatient, the extraction may be implemented either via working channels192,216 or upon the withdrawal of the entire instrument. In the lattercase, the severed specimen is carried in the chamber 160, 222 untiloutside of the patient.

Where a surgical operation results in a bleeding vessel, the vessel canbe coagulated with RF or injected with sclerosing or hemostatic agent.

Any diagnostic and surgical maneuvers described here can be performed inconjunction with external maneuvers, for example, laparoscopicmaneuvers. This laparo-endoluminal approach is generally known in thefield of surgery and may facilitate the performance and safety of theoperation while preserving the benefits of minimally-invasive approach.Although the invention has been described in terms of particularembodiments and applications, one of ordinary skill in the art, in lightof this teaching, can generate additional embodiments and modificationswithout departing from the spirit of or exceeding the scope of theclaimed invention. For example, rods 86 and 88 may be fixed to distaljaw 56 and slidably connected to shaft 50. Alternatively, rods 86 and 88may be fixed to both distal jaw 56 and shaft 50, in which case proximaljaw 54 is slidable along rods 86 and 88 alternately towards and awayfrom jaw 56. Also, more than two rods 86 and 88 may be provided forcoupling distal jaw 56 to instrument shaft 50.

In yet another alternative design, both jaws 54 and 56 are movable alongrods 86 and 88 during a clamping or closure stroke. Such a designfacilitates hemorrhoid occlusion without tearing of the tissues belowthe occluded tissue base. If only one jaw 54 or 56 is movable along rods86 and 88, then the entire instrument could be moved relative to thepatient during closure of the jaws to ensure against undesired tissuetears. Where the distal jaw 56 is slidable along rods 86 and 88, theentire instrument is pushed into the patient while the distal jaw ismoving in a proximal direction.

Accordingly, it is to be understood that the drawings and descriptionsherein are proffered by way of example to facilitate comprehension ofthe invention and should not be construed to limit the scope thereof.

1.-29. (canceled)
 30. A method of treating tissue comprising: insertinginto a body of a patient an endoscopic instrument having an expandablechamber in a collapsed configuration, the chamber having a distalportion, a proximal portion and an intermediate portion between thedistal and proximal portions; expanding the chamber from the collapsedconfiguration to an expanded configuration to increase a transversedimension of the chamber at the intermediate portion; inserting a distalportion of a working instrument into the chamber, the working instrumentlaterally extendable with respect to a longitudinal axis of theendoscopic instrument; and visualizing the distal portion of the workinginstrument by a visualization device which extends through a portion ofthe endoscopic instrument.
 31. The method of claim 31 wherein expandingthe chamber expands the chamber to only one side of the longitudinalaxis of the endoscopic instrument.
 32. The method of claim 31, whereinthe visualization device terminates adjacent the chamber.
 33. The methodof claim 31, visualizing the distal portion of the working instrumentincludes the step of angling the visualization device so it extendslaterally with respect to the longitudinal axis of the endoscopicinstrument.
 34. The method of claim 31 further comprising severing atissue mass positioned within the chamber and removing the severedtissue mass from the patient by at least one of (i) removing the severedtissue mass via the first channel, and (ii) removing the severed tissuemass by retaining the severed tissue mass in the chamber and withdrawingthe endoscopic instrument from the patient.
 35. The method of claim 31,further comprising receiving a polyp within the chamber and severing thepolyp from the body utilizing the working instrument inserted throughthe first channel of the endoscopic instrument.
 36. The method of claim31, further comprising illuminating at least one portion of the chamberor tissue provided at or protruding into the chamber to enable a visualinspection thereof.
 37. A system, comprising: a sheath, comprising: achannel configured to receive an endoscope, and a distal tissue engagingsurface, and a proximal tissue engaging surface, wherein the proximaland distal tissue engaging surfaces are adjustable to form a chamber inuse in a body lumen, the chamber configured to provide an increasedworking space within the body lumen; a working instrument having adistal portion positionable within the chamber; and an endoscopeextendable distal of the proximal tissue engaging surface to visualizeat least a portion of the chamber.
 38. The system of claim 37, furthercomprising a member axially movable relative to a longitudinal axis ofthe sheath to adjust a distance between the proximal and distal tissueengaging surfaces.
 39. The system of claim 38, wherein the member isoffset from the longitudinal axis of the sheath.
 40. The system of claim38, wherein the member is parallel to the longitudinal axis of thesheath.
 41. The system of claim 38, wherein the sheath includes firstand second channels with openings into the chamber, the workinginstrument extendable within one or both of the first and secondchannels.
 42. The system of claim 37, wherein the sheath comprises aworking channel, the working instrument extendible through the workingchannel.
 43. The system of claim 42, wherein the working instrument isconfigured for severing a polyp from a body within the chamber.
 44. Asystem, comprising: a sheath, comprising: a channel configured toreceive an endoscope, a distal tissue engaging surface, and a proximaltissue engaging surface, wherein the proximal and distal tissue engagingsurfaces are adjustable to form a chamber in use in a body lumen, thechamber configured to provide an increased working space within the bodylumen: a working instrument, wherein a distal portion of the workinginstrument is positionable within the chamber; and an endoscope movablewithin the chamber.
 45. The system of claim 44, further comprising amember axially movable relative to a longitudinal axis of the sheath toadjust a distance between the proximal and distal tissue engagingsurfaces.
 46. The system of claim 44, wherein the member is offset fromthe longitudinal axis of the sheath.
 47. The system of claim 44, whereinthe sheath includes first and second channels with openings into thechamber, the working instrument extendable within one or both of thefirst and second channels.
 48. The system of claim 44, wherein theendoscope is movable within the chamber to an angled position relativeto a longitudinal axis of the sheath.
 49. The system of claim 44,wherein the sheath comprises a working channel, the working extendiblethrough the working channel, the working instrument configured forsevering a polyp from a body within the chamber.